Field of the Invention
The invention relates to a motor-operated mechanism for electrical switching devices, which is intended in particular for circuit-breakers. The coupling of the mechanism to the circuit-breaker is possible through a knob or a latching mechanism.
Coupling to a knob is advisable in order to obtain optimum devices and make them as narrow as possible. In that case, motor-operated mechanisms which bring about snap-action closing of the circuit-breaker are known. Those are described, inter alia, in French Patent Application 2 476 906, European Patent Application 0 034 966 A1, European Patent Application 0 150 756 A2, corresponding to U.S. Pat. No. 4,649,244, and European Patent Application 0 506 066 A1. Those mechanisms are relatively complex. In contrast therewith, there are motor-operated mechanisms having a simpler type of construction for circuit-breakers which themselves have snap-action closing. Such a mechanism is described in German Patent DE 690 24 176 T2. Those are generally unsuitable for circuit-breakers without a snap-action mechanism, since the switching speed is too low. The remote-controlled mechanisms in most cases are screwed onto the circuit-breaker and are constructed specifically for the characteristics of the respective breaker. In order to activate the motor-operated mechanism by a programmable controller, an actuating current should be kept as small as possible. As a result, actuation through the use of an operating magnet or, as in European Patent Application 0 506 066 A1, tripping of a latch through the use of a tripping magnet, appear to be disadvantageous. Manual actuation must be possible at any time.